arch/csky/include/asm/cmpxchg.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2
   3 #ifndef __ASM_CSKY_CMPXCHG_H
   4 #define __ASM_CSKY_CMPXCHG_H
   5
   6 #ifdef CONFIG_CPU_HAS_LDSTEX
   7 #include <asm/barrier.h>
   8
   9 extern void __bad_xchg(void);
  10
  11 #define __xchg(new, ptr, size)                                  \
  12 ({                                                              \
  13         __typeof__(ptr) __ptr = (ptr);                          \
  14         __typeof__(new) __new = (new);                          \
  15         __typeof__(*(ptr)) __ret;                               \
  16         unsigned long tmp;                                      \
  17         switch (size) {                                         \
  18         case 4:                                                 \
  19                 smp_mb();                                       \
  20                 asm volatile (                                  \
  21                 "1:     ldex.w          %0, (%3) \n"            \
  22                 "       mov             %1, %2   \n"            \
  23                 "       stex.w          %1, (%3) \n"            \
  24                 "       bez             %1, 1b   \n"            \
  25                         : "=&r" (__ret), "=&r" (tmp)            \
  26                         : "r" (__new), "r"(__ptr)               \
  27                         :);                                     \
  28                 smp_mb();                                       \
  29                 break;                                          \
  30         default:                                                \
  31                 __bad_xchg();                                   \
  32         }                                                       \
  33         __ret;                                                  \
  34 })
  35
  36 #define xchg(ptr, x)    (__xchg((x), (ptr), sizeof(*(ptr))))
  37
  38 #define __cmpxchg(ptr, old, new, size)                          \
  39 ({                                                              \
  40         __typeof__(ptr) __ptr = (ptr);                          \
  41         __typeof__(new) __new = (new);                          \
  42         __typeof__(new) __tmp;                                  \
  43         __typeof__(old) __old = (old);                          \
  44         __typeof__(*(ptr)) __ret;                               \
  45         switch (size) {                                         \
  46         case 4:                                                 \
  47                 smp_mb();                                       \
  48                 asm volatile (                                  \
  49                 "1:     ldex.w          %0, (%3) \n"            \
  50                 "       cmpne           %0, %4   \n"            \
  51                 "       bt              2f       \n"            \
  52                 "       mov             %1, %2   \n"            \
  53                 "       stex.w          %1, (%3) \n"            \
  54                 "       bez             %1, 1b   \n"            \
  55                 "2:                              \n"            \
  56                         : "=&r" (__ret), "=&r" (__tmp)          \
  57                         : "r" (__new), "r"(__ptr), "r"(__old)   \
  58                         :);                                     \
  59                 smp_mb();                                       \
  60                 break;                                          \
  61         default:                                                \
  62                 __bad_xchg();                                   \
  63         }                                                       \
  64         __ret;                                                  \
  65 })
  66
  67 #define cmpxchg(ptr, o, n) \
  68         (__cmpxchg((ptr), (o), (n), sizeof(*(ptr))))
  69 #else
  70 #include <asm-generic/cmpxchg.h>
  71 #endif
  72
  73 #endif /* __ASM_CSKY_CMPXCHG_H */